Additive for mineral oil



2,830,019 ADDITIV E FOR MINERAL OIL Ellis K. Fields, Chicago, Ill., and Allen E. Brehm, Griiiith,

Ind., assignors to Standard Oil Company, Chicago, 111., a corporation of Indiana No Drawing. Application September 29, 1954 Serial No. 459,208

9 Claims. (Cl. 25233.6)

This invention relates to hydrocarbon oil compositions. More particularly, the invention relates to hydrocarbon oils containing additives which improve color stability, corrosivity, etc. thereof.

Hydrocarbon oils in general are susceptible to deterioration by contact with the atmosphere or metals. This deterioration manifests itself in degradation of the color of the hydrocarbon oil. Or the deteriorated oil becomes ineffective to protect the surface of the metal with which it is contacted from corrosion as manifested by rust in the case of ferrous metals and the formation of undesired surface films, as in the case of copper.

The demand of modern industry, the automobile, the airplane, are such that protection of machinery is imperative. Such protection is desirably obtained by the use of hydrocarbon oils which are stable in use, even though in certain uses such as in domestic heating establishments the deterioration of the oil with respect to color may be of no significance with respect to its use. Nevertheless, consumer demand requires that domestic heating oils be color stable in storage.

The quality of oils derived from petroleum by distillation with respect to color stability, corrosivity, etc. may be improved by many refining techniques. However, even refined oils are susceptible to a greater or lesser degree of deterioration in storage or in use. The most stable oils now in use contain an additive or additives which impart to the oil the desired qualities of stability, etc.

An object of the invention is a hydrocarbon oil composition of improved resistance to deterioration in storage and use. Another object of the invention is a petroleum distillate composition of improved corrosivity toward fen'ous metal. Still another object is a'petroleum distillate fuel of improved color stability in storage. A-

particular object is a gasoline of good anti-rust characteristics. Another particular object is a turbine oil of good anti-rust characteristics. Other objects willbecome apparent in the course of the detailed description of the invention. g

The objects of the invention are attained by the use of a hydrocarbon oil, particularly a petroleum distillate fraction, containing an effective amount of an additive derived by the reaction of a defined amine and a hereinafter defined amino-carboxylic acid.

The amino-carboxylic acids which are suitable for the purposes of the invention are represented by the configuration:

(I) (011. .00 on (OHzhO on (II) RNKoHnmo on 2 wherein x is an integer from 1 to 3 and preferably x is 1; R is a member selected from the class consisting of (a) hydrogen,

wherein y is an integer from 2 z is an integer from 1 to 3.

Iminodiacetic acid is an example wherein R is hydrogen and x is 1. Ethylenediaminetetraacetic acid is an example wherein R is member (b) and y is 2 and x is 1. Tetraethylenepentamineheptaacetic acid is an example of an acid where R is member (c), x is l, y is 2 and z is 3.

The amino acids of the invention may also be described as amino aliphatic carboxylic acids wherein at least 1 amino nitrogen holds 2 carboxyalkyl groups.

The amines suitable for the purposes of the invention are: (1) aliphatic amines, either primary, secondary, or tertiary wherein at least one aliphatic group contains at least 8 carbon atoms, and (2) heterocyclic amines wherein at least one ring nitrogen has a valence which is not part of the ring structure, excluding the pyrrole types, and which contain at least one aliphatic substituent having at least 8 carbon atoms therein. Illustrative examples of these amines are octylamine, decylatnine, tetradecylamine, octadecylamine, dioctylamine, dioctadecylamine, stearylimidazoline, and oleylimidazoline.

The preferred amines are the fatty acid amines. Particularly desirable are those mixtures of amines which are obtained from natural vegetable oils, such as palm oil, coconut oil, soya bean oil, tall oil, and cottonseed oil. Also particularly suitable is the mixture of amines derived to 3 and preferably 2; and

from tallow. Of even greater interest are the high molecular weight amines which are obtained as fraction in the distillative purification of the mixture of amines prepared from the above-named oils and fats. These amines are commercially available under the designation corresponding to the amine -product from the particular oil or fat, e. g., tallowamine bottoms, and cocoamine bottoms. The bottoms product amines have one disability in that the quality of the material is variable and therefore the amine salt of the amino-carboxylic acid produced therefrom will vary in quality from batch to batch of the amine bottoms material.

The amine salts of amino-carboxylic acids utilizable as hydrocarbon oil additives are readily prepared by heating the desired amine and the desired amino-carboxylic acid at a temperature below the decomposition temperature of the individual components for a suitable period of time. The temperature and the time are dependent upon the particular reactants used. In general, the temperature at which the reaction is carried out is between about 30 C. and about 200 C.; the time needed for the reaction to be completed will be between about 15 minutes and about 3 hours. It is preferred to utilize a temperature between about C. and about 180 C.; the corresponding time will be dependent on the type of reactants charged.

The relative amounts of amine and amino-carboxylic acid utilized is dependent upon the number of carboxylic acid groups in the acid and also upon the degree to which the carboxylic acid groups are to be reacted. When it is desired to react all the carboxylic acid groups, it is preferred to operate with an excess of amine over the stoichiometric requirement. In general, the molar a bottoms 2,880,019 H a n r a ratio of amine to acid is between about 0.5 and 1.5 of the stoichiometric requirement for reaction with all the carboxylic groups in the acid. It is preferred to operate with a molar ratio .of amine and amino-carboxyh'c acid such that all the carboxyliegroups will be reacted, i. e., at least the stoichiometric requirement.

The amine salt of amino-carboxylic acid is readily prepared by admixture of the desired amounts of the reactants and heating the mixture to the desired temperature and maintaining said mixture at that temperature for the necessary time, The appearance of the reactants changes when the reaction begins and completion of the reaction is observed visually by disappearance of the individual reactants. The reaction product mixture is cooled to room temperature and may be utilized as an 7 additive without further treatment. However, when an excess of one reactanthas been used, it may be desirable to purify the reaction product mixture. This purification is readily carried out by treating the mixture with solvent such as the insoluble material and recovering the purified rcaction product, i. e., the amine salt of amino-carboxylic acid, by evaporating away the solvent.

The hydrocarbon oil which forms the major component of the composition of the invention may be any liquid hydrocarbon oil which is susceptible to deterioration by exposure to oxidizing conditions or metal surfaces in use or in storage. The oils which are particularly benefited are petroleum distillates. By the term petroleum distillate, it is understood to include any oil of petroleum derivation which may be vaporized without thermal decomposition either at atmospheric pressure or by the use of vacuum. These petroleum distillates may be those boiling in the naphtha range, i. e., from about 100 to about 425 F., in the heavier-than-gasoline range, i. e., from about 330 to about 650- F. or may be in the lube oil range; particularly in the naphtha and heavier-thangasoline range materials the distillate maybe either a virgin or a cracked distillate or a mixture thereof. The cracked distillate may be derived either by thermal cracking, coking, or by catalytic cracking. Naphthas which have. been derived by thermal reforming or catalytic reforming are also benefited by the presence of the defined amine salts of aminocarboxylic acids. Illustrations of petroleum distillates which may form the major component of the composition of the invention are motor gasoline, aviation gasoline, kerosene, diesel oil, heater oil, furnace oil, turbine oil and motoroil. The lubricating oil components may be either untreated distillates,

acid refined distillates, or solvent extracted distillates.

benzene or hexane, filtering to remove Furthermore, motor oils may be those very high boiling materials which are obtained by liquid propane treating of residuums.

The hydrocarbon oil is the major component of the composition of the invention. The defined amine salts of amino-carboxylic acid is present in an amount sufficient to improve the stability of the oil against deterioration in I the particular use thereof. Generally only a very small amount of amine salt of amino-carboxylic acid is utilized. The particular amount used is dependent on the particular use of the composition, but in general will be between about 0.0003 and about 2% by weight of the composition. 0.002 and 0.05 by weight. Expressed in other words, the usage of a defined amine salt of amino-carboxylic acid will be between about 1 pound and about 6000 poundsper 1000 barrels (42 gal.) of petroleum distillate.

Examples of the defined amine salts of amino-carboxylic acids are set out below. Illustrations of the compositions containing various amounts of illustrative examples and the beneficial results derived from the presence of the defined salt in petroleum distillate are set.

out as determined by various tests. It is to be understood that the examples of the defined amine salts of aminocarboxylic acids and the illustrative petroleum distillate More usually the usage will be between about compositions containing these salts are illustrative only and do not limit the scope of the invention.

Salt A.-The amine used in this example is sold by Armour & Co. under thename, Tallowamine Bottoms. This material is obtained as a bottoms product from the distillation of thespectrum of amines produced from tallow. The tallowamine bottoms utilized in this example contained 3.55% nitrogen and had a molecular weight of 42 1. This material is predominantly the secondary amine with the remaining portion primary amine. Ethyl-- enediaminetetraacetic acid-25 g. (0.086 mole) and 150 g. (0.356 mole) of tallowamine bottoms were stirred for 15 minutes at 150 C. The reaction product was a clear brown .liquid which analyzed 4.40% nitrogen. This liquid product was completely soluble in an SAE 30 lubricating oil.

Salt B.--The amine utilized in this example is sold by Armour & Co. under the designation Armeen T. This.

material is principally octadecylaminc and has a molecular weight of 310. Ethylencdiaminetetraacetic acid- 12.5 g.'(0.043 mole) and 48 g. (0.155 mole) of Armeen T were stirred at 150 C. for 30 minutes. The reaction product was a clear light brown liquid which contained 7.42% nitrogen and had a molecular weight of 1033. This material was very soluble in lube oil.

Salt C.'In this example, the amine used is sold by Armour & Co. as Armeen 2C. This amine contains about of secondary amines and has a mole combining weight of 435. Its approximate composition-with respect to alkyl'groups is oct'yl-8%, decyl-9%, dodecyl-47%, tetradecyl-l8%, hexadecyl'8%, and octadecyll0%. Armeen 2C (0.08 mole) and 0.02 mole of ethylenediaminetetra-acetic acid were stirred at 148 C. for 15 minutes. 35.2 g. of a cream-colored solid was obtained. The product contained 4.45% nitrogen and was soluble in lube oil.

Salt D.-In this example, the amine was purchased as Alroamine S. This materal is an imidazoline having the following structure: 7

Alroamine and 8.76 g. (0.03 mole) of ethylenediaminetetraacetic acid were stirred at 150 C. for 15 minutes. 50.7 g. of a clear light brown liquid product were obtained. The product contained 8.08% nitrogen and was soluble in lubricating oil. The alkyl imidazolines are strongly basic, i. e., have an ionization constant of greater than 10- as reported by Ladenburg, Berichte 27, 2952 (1894).

Salt F.'Armeen T, 150 g. (0.48 mole), was reacted with 25 g. (0.086 mole), of ethylenediaminetetraacetic acid at C. for 10 minutes. The hot reaction product was a clear orange liquid which changed to waxy solid on cooling to room temperature. The waxy solid was soluble in gasoline and lube oil. The product contained 5.12% nitrogen. 7

Salt G.--In this example, the amine utilized was prin cipally t-octadecylamine sold under the name of Primene JMR. 100 g. of this amine and 20 g. of

minutes. The product was clear orange colored viscous liquid containing 5.47% nitrogen and was soluble in gasoline.

Salt H.-The amine in this example is sold by Armour & Co. under the designation Duomeen S. This amine has the structure RNH(CH NH were R is an aliphatic group containing 18 carbon atoms. 0.46 mole of Duomeen S and 0.86 mole of ethylenediamintetraacetic acid were stirred at 155 C. for 20 minutes. The product was an orange-yellow in color and contained 7.91% nitrogen and was soluble in gasoline.

Salt I.In this example, the amine used is sold by Armour & Co. under the name, Cocoamine Bottoms. This material is the bottoms product from the distillation of the spectrum of amines made from coconut oil. 150 g. of the cocoamine bottoms and g. of ethylenediaminetetraacetic acid were stirred at 148 C. for 15 minutes. The product was diluted with 300 m1. of hexane and filtered. The hexane was removed by evaporation. The brown waxy solid product was completely soluble in gasoline and lube oil. A yield of 173 g. of product containing 2.99% nitrogen was obtained.

Salt J.-Tallowamine bottoms (0.15 mole) and ethylenediaminetatraacetic acid (0.05 mole) were stirred at 166 C. for 20 minutes. The hot product was a clear brown liquid which changed to a solid at room temperature. The product contained 4.77% nitrogen.

Salt K.Tallowamine bottoms (0.2 mole) and ethylenediaminetatraacetic acid (0.1 mole) were stirred at 166 C. for 20 minutes. The hot product was filtered to remove a small amount of insoluble material. The prodnot at room temperature was a light brown Waxy solid containing 5.02% nitrogen.

Salt L.-Iminodiacetic acid (0.1 mole) and 0.2'rnole of tallowamine bottoms were stirred at about 170 C. The reaction product was a light brown waxy solid which was completely soluble in gasoline. The product of this reaction contained 5.06% nitrogen.

Salt M.Iminodiacetic acid (0.1 mole) and 0.1 mole of tallowamine bottoms were stirred at about 170 C. for 20 minutes. The reaction product was a brown waxy solid at room temperature which contained 5.15% nitrogen and was soluble in gasoline.

RUST INHIBITION IN LUBRICATING OIL The efiectiveness of these additives in inhibiting rusting is demonstrated by the results obtained in the A. S. T. M. test for rust prevention, having the designation D665-47T. In this test, 300 cc. of the oil to be tested are placed in a 400 cc. lipless glass beaker and heated to 140 F. in an oil bath and the oil sample agitated with a stirrer maintained at about 1000 R. P. M. When the temperature of the oil sample reaches 140 F., a cleaned test strip of cold rolled steel is suspended in the oil and the stirring continued for thirty minutes to insure complete Wetting of the steel specimen. Thirty cc. of distilled water are then carefully added to the beaker andifthe stirring continued for 48 hours. At the end of this time the steel specimen is removed from the beaker, washed with naphtha and visually inspected for the presence of rust.

The tenacity with which the lubricating oil clings to the metal was measured by modifying the D665 test. The tenacity test is carried out under the same conditions as for the D665 test except that the beaker contains 330 ml. of water instead of water and oil. The test is carried out on a strip which has just completed the D665 test; the oil and water are dumped from the beaker and 330 ml. of water are added to the beaker. The strip is then subjected to the conditions of the D665 test except for the absence of the oil. At the completion of the time, the degree of rusting of the strip. is determined visually. This test gives an indication of how readily the lubricating oil is washed from the metal surface by hot water. An'

oil which develops even a moderate amount of rust in the D665 test will give very severe rusting in the tenacity test. a

The oil used in these tests was a turbine oil having the following characteristics:

The results of the tests using this turbine oil and various amine salts of amino-carboxylic acids are set out 1n Table I.

Table I Test No. Additive Percent D665 rust Tenacity, rust;

present 1 None Severe 2. Salt A 0. 03 Slight 3 do- 0.05 None-. None.

0.10 do Do. 0.03 0.05 Do. 0.10 Do. 0.01 0.03 Do. 0.01 0.03 Do. 0.01 0.03 Do.

These tests show that not only do these additive-containing oils give excellent protection against the formation of rust in the D665 test, but they continue to protect the metal in the severe tenacity test.

TEST 14 For purposes of comparison, a salt of glutamic acid and tallowamine bottoms was prepared by reacting 0.05 mole of the acid and 0.1 mole of the bottoms at 148 C. and 15 minutes time. The product was a brown solid containing 4.23% nitrogen which was soluble in lube oil. The product was added in an amount of 0.10% to the above-described turbine oil and the salt-containing oil was then tested according to the D665 test. The amount of rusting of the test specimen was severe; there was no appreciable difference between the salt-containing oil and the straight turbine oil insofar as rusting characteristics were concerned.

RUST INHIBITION IN GASOLINE The ability of the defined amine salts of amino-carboxylic acids to inhibit rust formation in gasolines was tested by the following method: A test specimen was prepared from a strip of SAE 1020 grade steel by sanding with a belt sander; the test strip measured one-half inch x oneeighth inch by six inches. Each strip was washed with hot naphtha and with acetone before being placed in a tall form four ounce bottle. 100 m1. of motor gasoline was added to the strip-containing bottle and the bottle stoppered. The bottle was allowed to stand for one-half hour. Then 10 ml. of ordinary tap water was added to the bottle, the stopper was replaced, and the bottle rolled on a horizontal surface for about 1 minute. The bottle was returned to a vertical position and held at room temperature of about F. for a period of 16 hours. At the end of this time, the strips were removed from the bottle and the degree of rusting of the portion of the strip exposed to the gasoline layer and the portion exposed to the water layer determined separately.

The results of tests on ordinary motor gasoline and amino-carboxylic acids are set out in Table II.

1 Table II Rust on surface exposed to- P ercent i present Test No. .Addltive Gasoline Water Moderate. Slight None.

Do; Slight.

Do. Moderate.

These data show that extremely small amounts of these amine salts reduce rust forming tendencies of motor gasoline in the presence of water to a very small amount. it is of particular interest that in Test 17 not only was the strip protected against corrosion in the gasoline layer, but also the adherent layer of additive-containing gasoline on the metal protected the strip from corrosion in the water layer.

Tests were made to note the effect of the additives on the octane number, of the gasoline; These tests showed that the presence of these defined amine salts in gasoline has no appreciable effect on the octane number of the gasoline to which the salts have been added.

COLOR STABILIZATION The ability of the defined amine salts to stabilize oils against color degradation was tested by the use of an accelerated test. In this test, a measured amountof the oil is introduced into a beaker and the beaker is maintained in an oven at a tempertaure of 200 F. for a time of 200 hours. During the test, the oil is exposed to atmospheric oxygen.

The color stability of petroleum distillate fuels is of particular concern because of the association by the con sumer of the color stability and the quality of the oil. Tests were carried out using a heater oil which is sold for domestic heating purposes. This heater oil is a refined virgin petroleum distillate having the following characteristics: Degrees, APT-41.5; ASTM distillation-initial-330 F., 50%430 F. and max.565 F.; total sulfur-about 0.37 weight percent and sweet to the doctor test. In the tests, several oils having the above characteristics, but exhibiting ordinary variation in initial color and in color stability were utilized as the base oils.

The results of the color stabilization tests on heater oils are set out in Table III. In Table III, the tests utilizing base oils are designated by an integer and the additivecontaining base oils are set out by the corresponding integer and a letter. The colors were measured by the Saybolt method (SAY in the table) or by the ASTM method (NPA in the table). The aged color is the color of the oil at the completion of the accelerated test.

Table III Test No Additive Percent Initial color Aged color present The data in Table III show that heater oils are readily ill stabilized against any significant color loss by the use of extremely small amounts of the defined amine salts.

TESTS 27 AND 27a In these tests, a fuel sold for use in jet planes was the base oil. This jet fuel had the following inspections:

API 51.1 ASTM distil., "F 143 10% 227 50% 337 90% 418 Max 485 Sulfur, wt. percent 0.13 Mercaptan Sweet lbs/i000 bbls. of Salt G were added to a fresh sample the jet fuel and the additive-containing jet fuel was subjected to the accelerated test. The aged color of the additive-containing jet fuel was +18 Saybolt. This test shows that the amine salts are able to stabilize color in a fuel that is primarily a gasoline range petroleum distillate.

TEST 28 In addition to good color stability, distillate fuels must not form significant amounts of deposits in the domestic burner. The Junger burner is an extremely severe test for burner deposit forming tendencies of distillate fuels. In order to determine the effect of the defined amine salts on the burner deposit forming tendencies of the heater oils, a test was made under standard conditions with a .lunger burner and burning 50 gallons of fuel. The base oilutilized in Test No. 23 Wasburned in a Jungerburner and gave about 7 grams of deposits. The test was repeated utilizing the oil containing 5 lbs./ 1000 bbls. of Salt G. After burning 50 gallons of the additive-containing oil, only 6.3 grams of deposits had been formed. Thus, within the error of the burner test, the presence of the defined amine salt has no appreciable effect on the burner deposit forming tendencies of heater oils.

INHIBITION OF COPPER CORROSION was determined by the ICCS method which is described by I. A. Bolt in the Oil & Gas Journalof August 9, l947.' In this method, a number of zero indicates a perfect strip and the higher the number, the more corrosive the oil. The results of these tests are set out in Table IV:

Table IV Test No. Additive Percent Copper present strip None 5- 0.05 4 0. 10 0+ These tests show that the amine salt is effective in re ducing the corrosivity of an oil toward copper where sul fur compounds are the cause of the corrosion. However, fairly large amounts of the defined amine salt are needed to more or less completely inhibit the corrosivity of the oil.

It is to be understood that the composition of the invention is not limited to a hydrocarbon oil as the predominant component and the defined amine salts as'the minor component. The composition may contain, in addition to the defined amine salts, the additives which are conventionallyadded to the particular oil. Thus, inthe case of motor gasolines, there may also be present anti-oxidants. In the case of heater oils, there may be present additives which reduce sludge forming tendencies of the 9 oils. In the case of motor oils, there may be present detergents which maintain in dispersion decomposition products. Furthermore, it is pointed out that the various amine salts are not equally eifective for all uses or for any particular use and therefore the amounts of each amine salt needed to accomplish the desired improvement may diifer. However, the amount needed may be determined very readily by the use of one of the standard tests, such as have been described herein.

Thus having described the invention, what is claimed is:

l. A hydrocarbon oil composition comprising a major proportion of a liquid petroleum distillate and between about 0.0003 and about 2% by weight, based on composition of an amine salt of an amino-carboxylic acid obtained by intermingling, at a temperature between about 30 C. and about 200 C. such that a reaction product is obtained, a molar ratio of amine to acid between about 0.5 and 1.5 of the stoichiometric requirement to react all the carboxylic groups in the acid, (A) an amine selected from the class consisting one aliphatic group contains at least 8 carbon atoms and (2) imidazolines having an aliphatic substituent containing at least 8 carbon atoms, with (B) an amino-carboxylic acid having the configuration.

wherein R is selected from the class consisting of (a) hydrogen,

([1) (CHz)=COOH (GHmOOOH wherein x is an integer from 1 to 3, y is an integer from 2 to 3.

of 1) aliphatic amines wherein 2. The composition of claim 1 wherein said distillate is a heater oil.

3. The composition of claim 1 wherein said distillate is a jet fuel.

4. The composition of claim 1 wherein said distillate is a lubricating oil.

5. The composition of claim 1 wherein said salt is obtained by reacting tallowamine bottoms and ethylenediaminetetraacetic acid at a temperature between about 140 C. and 180 C.

6. The composition of claim 1 wherein said salt is obtained by reacting cocoamine bottoms and ethylenediaminetetraacetic acid at a temperature between about 140 C. and 180 C.

7. The composition of claim 1 wherein said salt is obtained by reacting octadecylamine and ethylenediaminetetraacetic acid at a temperature between about 140 C. and 180 C.

8. The composition of claim 1 wherein said salt is obtained by reacting tallowamine bottoms and iminodiacetic acid at a temperature between about 140 C. and 180 C. l

9. The composition of claim 1 wherein said arniue is stearylimidazoline.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A HYDROCARBON OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF A LIQUID PETROLEUM DISTILLATE AND BETWEEN ABOUT 0.0003 AND ABOUT 2% BY WEIGHT, BASED ON COMPOSITION OF AN AMINE SALT OF AN AMINO-CARBOXYLIC ACID OBTAINED BY INTERMINGLING, AT A TEMPERATURE BETWEEN ABOUT 30*C. AND ABOUT 200*C. SUCH THAT A REACTION PRODUCT IS OBTAINED, A MOLAR RATIO OF AMINE TO ACID BETWEEN ABOUT 0.5 AND 1.5 OF THE STOICHIOMETRIC REQUIREMENT TO REACT ALL THE CARBOXYLIC GROUPS IN THE ACID, (A) AN AMINE SELECTED FROM THE CLASS CONSISTING OF (1) ALIPHATIC AMINES WHEREIN ONE ALIPHATIC GROUP CONTAINS AT LEAST 8 CARBON ATOMS AND (2) IMIDAZOLINES HAVING AN ALIPHATIC SUBSTITUENT CONTAINING AT LEAST 8 CARBON ATOMS, WITH (B) AN AMINO-CARBOXYLIC ACID HAVING THE CONFIGURATION. 